Machine to machine (m2m) frame within a frame

ABSTRACT

A method for use in a wireless communications system includes transmitting M2M signals in an allocated narrow portion of bandwidth in a wideband structure. The allocated portion of the bandwidth may be allocated to narrow band M2M (NB-M2M) devices using a low complexity narrowband technology to access a frame structure within an existing wideband deployment.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/984,270, filed Oct. 17, 2013; which claims the benefit of U.S. PatentApplication No. 61/441,119, filed Feb. 9, 2011, and PCT application No.PCT/US2012/024472, filed Feb. 9, 2012, the contents of which are herebyincorporated by reference herein.

FIELD OF INVENTION

This application is related to wireless communications.

BACKGROUND

Machine to Machine (M2M) devices may use a lower complexity narrowbandtechnology to access a frame structure within an existing widebanddeployment. In such a deployment, a base station may allocate a narrowpart of the spectrum specifically for M2M use.

By embedding a narrowband structure inside a wideband structure, a basestation may manage low bandwidth M2M along with regular network use,while the M2M devices may be made less complex and with lower powerconsumption and lower cost than full-band devices.

M2M devices that process narrow band radio frequency (RF) channels maybe referred to as Narrow-Band M2M (NB-M2M) Devices. M2M devices maybelong to one of the following three classes based on their capabilityof band processing: (1) Narrow-band only M2M devices that may onlyprocess narrow band (e.g., 1.25 MHz or 1.08 MHz); (2) Wide-band only M2Mdevices; or (3) Capable of processing both narrow-band and wide-band,but one at a time, i.e. configurable where the wide-band capability maybe limited to some specific cases. For example, an M2M device capable ofprocessing both narrow-band and wide-band may use wide-band for networkentry.

In general, base station (BS) support for NB-M2M operations may includethe following: (1) a BS scheduler may allocate the M2M regions to meetthe quality of service (QoS) requirements for M2M traffic and also tominimize the impact on non-M2M devices; (2) a BS may provide NB-M2Mregion specific PHY support, (for example, NB-M2M region PHYsynchronization signals, downlink/uplink (DL/UL) control signals, suchas MAPs, UL ranging and feedback, and data bursts); and (3) a BS mayprovide the NB-M2M device specific MAC support to improve the systemefficiency for NB-M2M operation, (for example, M2M device specificbandwidth management and allocation mechanisms, M2M device specificpower saving procedures with long sleep/idle intervals). The BS may be alogical node in wireless communication systems that facilitates wirelesscommunication between a subscriber station (SS)/wirelesstransmit/receive unit (WTRU) and a network.

SUMMARY

A method for use in a wireless communications system includestransmitting M2M signals in an allocated narrow portion of bandwidth ina wideband structure, wherein the allocated portion of the bandwidth isallocated to narrow band M2M (NB-M2M) devices using a low complexitynarrowband technology to access a frame structure within an existingwideband deployment.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A;

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A;

FIG. 2 is an example of M2M frame-within-a-frame for LTE;

FIG. 3 is an example of 802.16e OFDMA TDD frame structure with onlymandatory zone;

FIG. 4 is an example of 802.16e TDD frame structure with NB-M2M regionallocated in AMC zone;

FIG. 5 is an example of 802.16e TDD frame structure with NB-M2M regionallocated in AMC zone with FCH included in the NB-M2M region;

FIG. 6 is a table of 128 FFT OFDMA AMC subcarrier allocations;

FIG. 7 is an example of 802.16m TDD frame supporting legacy 802.16eoperation; and

FIG. 8 is an example of 802.16m with wireless MAN-OFDMA legacy frameoperating for NB-M2M.

DETAILED DESCRIPTION

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals and may include userequipment (UE), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the core network 106.

The RAN 104 may include eNode-Bs 140 a, 140 b, 140 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 140 a, 140 b, 140c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 140 a, 140 b, 140 c may implement MIMO technology. Thus,the eNode-B 140 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 140 a, 140 b, 140 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1C, theeNode-Bs 140 a, 140 b, 140 c may communicate with one another over an X2interface.

The core network 106 shown in FIG. 1C may include a mobility managementgateway (MME) 142, a serving gateway 144, and a packet data network(PDN) gateway 146. While each of the foregoing elements are depicted aspart of the core network 106, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 142 may be connected to each of the eNode-Bs 142 a, 142 b, 142 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 142 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 142 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 144 may be connected to each of the eNode Bs 140 a,140 b, 140 c in the RAN 104 via the S1 interface. The serving gateway144 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 144 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 144 may also be connected to the PDN gateway 146,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 106 may facilitate communications with other networks.For example, the core network 106 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 106 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 106 and the PSTN 108. In addition, the corenetwork 106 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

A Machine to Machine (M2M) device may be configured to use a lowcomplexity narrowband technology to access a frame structure within anexisting wideband deployment. More specifically, a base station may beconfigured to allocate a narrow part of the spectrum specifically forM2M use. By embedding a narrowband structure inside a widebandstructure, one base station may manage low bandwidth M2M along withregular network use, while the M2M devices may be made less complex andwith lower power consumption and lower cost than full-band devices.

M2M devices that process narrow band radio frequency (RF) channels maybe referred to as Narrow-Band M2M (NB-M2M) Devices. M2M devices maybelong to one of the following three classes based on their capabilityof band processing: (1) Narrow-band only M2M devices that may onlyprocess narrow band (e.g., 1.25 MHz or 1.08 MHz); (2) Wide-band only M2Mdevices; or (3) Capable of processing both narrow-band and wide-band,but one at a time, i.e. configurable where the wide-band capability maybe limited to some specific cases. For example, an M2M device capable ofprocessing both narrow-band and wide-band may use wide-band for networkentry.

In general, base station (BS) support for NB-M2M operations may includethe following: (1) a BS scheduler may allocate the M2M regions to meetthe quality of service (QoS) requirements for M2M traffic and also tominimize the impact on non-M2M devices; (2) a BS may provide NB-M2Mregion specific PHY support, (for example, NB-M2M region PHYsynchronization signals, downlink/uplink (DL/UL) control signals, suchas, MAPs, UL ranging and feedback, and data bursts); and (3) a BS mayprovide the NB-M2M device specific MAC support to improve the systemefficiency for NB-M2M operation, (for example, M2M device specificbandwidth management and allocation mechanisms, M2M device specificpower saving procedures with long sleep/idle intervals). The BS may be alogical node in wireless communication systems that facilitates wirelesscommunication between a subscriber station (SS)/wirelesstransmit/receive unit (WTRU) and a network. For example, a logical nodemay be NB/eNB in 3GPP systems or BS/ABS in 802.16 systems.

Some existing multicarrier systems may use a fixed subcarrier spacingthat may be independent of the bandwidth in use. Fixed subcarrierspacing (either 15 kHz or 7.5 kHz in the case of LTE) generally meansthat a radio operating in a 1.25 MHz band would have subcarriers spacedthe same distance apart as a radio operating in a 20 MHz band. Onedifference between the two radios is that the radio operating in the1.25 MHz band operates with a sample rate 16 times slower than the radiooperating in the 20 MHz band. Another difference between the two is thatthe narrower band allows for a less expensive radio as well as a lesscomplex and lower power baseband processor (e.g. 128 point FFT insteadof a 2048 point FFT).

In other multicarrier systems, the preamble and synchronization processmay be confined to the “center” 72 carriers, with a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),and a broadcast channel (BCH) all confined to this area. If the M2Mdevices are tuned to this part of the band, they may receive the sameinformation as their full-bandwidth counterparts. Following this, anM2M-specific frame structure may remain on these center carriers, whileother resources can be allocated to wideband devices. FIG. 2 illustratesan example of M2M frame-within-a-frame for LTE.

The smallest specified channel bandwidth for LTE, for example, may be1.4 MHz; (using 6 resource blocks). Using localized subcarrierallocations, downlink (OFDM) and uplink (DFTS-OFDM) transmissions forM2M devices may be limited to the same inner 72 subcarriers (6 resourceblocks) used for PSS 202, SSS 204, and BCH 206. Some higher layer frameplanning may be required to allow the M2M specific frames 208 to coexistwith regular data frames.

Similarly, FIG. 3 illustrates an example of 802.16e OFDMA (OrthogonalFrequency Division Multiplexing Access) TDD (Time Division Duplex) framestructure with only mandatory zone. The frames show uplink 302, anddownlink 304, as well as the preamble 306, DL-MAP 308, FCH 310, rangingchannel 312, and bursts including, for example, DL bursts 314 ₁₋₁₁ andUL bursts 316 ₁₋₅. A separate synchronization signal (not shown) may berequired for the M2M devices because an 802.16 preamble may span theentire wide band. For the downlink in an 802.16e system, subcarriermapping such as Band Adaptive Modulation and Coding (Band AMC) may beused to allocate a portion of the bandwidth to narrowband M2M devices.In this case, the regular frame structure may be used, but once themandatory transmissions are complete, the M2M preamble may be sent andany downlink transmissions specific to M2M devices may be identified bya special M2M MAP, followed by the data. Similarly, M2M uplink spacewithin the special narrow band may be allocated by the base station andused by the M2M devices.

FIG. 4 illustrates an example of 802.16e TDD frame structure 400 withNB-M2M region allocated AMC zone 402, as well as the preamble 404,partial usage of sub-carriers (PUSC) zone 406, full usage ofsub-carriers (FUSC) 408, and corresponding uplink PUSC and AMC zones418, 420. Bursts 414, 416 are also shown. An issue that may requireparameter adjustment is the subcarrier spacing used for variousbandwidths in 802.16e. The sampling frequency, F_(s), is calculated asfollows: F_(s)=floor (n·BW/8000)·8000, where it is the sampling factor.For bandwidths 1.25 MHz, 5 MHz, 10 MHz, and 20 MHz, this sampling factoris the same: 28/25. Subcarrier spacing is calculated as:Δf=F_(s)/N_(FFT), where N_(FFT) is the smallest power of two greaterthan the number of subcarriers in use, in this case, for 1.25 MHz, 5MHz, 10 MHz, and 20 MHz, N_(FFT) is 128, 512, 1024, and 2048,respectively.

For other bandwidths in 802.16e, the subcarrier spacing may not matchthe value for the 1.25 MHz band and changes to the parameters for thesebands may be required.

For the M2M preamble 410 in the 802.16e configuration, if the existing1.25 MHz parameters may be used, then the preamble defined for the 1.25MHz band may be embedded within the downlink frame to allow the M2Mdevice to synchronize to the base station in the same manner currentlydefined in 802.16e. In the Uplink subframe, the M2M Ranging subchannel412 may also be required.

FIG. 4 also shows an example of using a FDM (Frequency DivisionMultiplexing) way to accommodate both legacy wide-band traffic andnarrow-band M2M traffic in an 802.16e frame. The presence of NB-M2Mtraffic in an 802.16e frame may also be supported in a TDM (TimeDivision Mulipexing) manner or a combined FDM and TDM manner. Forexample, a DL NB-M2M region may be allocated in full or in any portionof an AMC zone.

FIG. 5 illustrates an example of 802.16e TDD frame structure 500 withNB-M2M region allocated in AMC zone with Frame Control Header (FCH) 502included in the NB-M2M region, for example, in the M2M DL-MAP, as shown.This is another example of using a FDM way to accommodate both legacywide-band traffic and narrow-band M2M traffic in an 802.16e frame. Inthis case, an FCH is included in the frame to allow 802.16e narrow bandmobile stations (MSs) to use this portion of the frame.

To support the NB-M2M operation in an 802.16e OFDMA system, the BSscheduler allocates NB-M2M regions in the 802.16e OFDMA frames, as shownin the example in FIG. 4. The available air link resource to the legacy802.16e subscriber stations (SSs)/MSs is reduced due to the introductionof the NB-M2M region. However, such impact may be minimized by carefullyscheduling such NB-M2M regions.

One way to minimize this impact is to have a traffic load dependantscheduling of the NB-M2M regions, with which the BS scheduler allocatesthe NB-M2M regions based on the traffic load of the legacy SSs/MSs,(i.e., the non-M2M traffic). For example, based on some predefinedthresholds, the non-M2M traffic load may be classified as high, medium,and low. When the non-M2M traffic load is high, during peak hours,minimum NB-M2M regions are scheduled to meet the need of transportingthe delay-sensitive M2M data, such as alarm/exception reporting. Whenthe non-M2M traffic load is low (e.g., midnight), more NB-M2M regionsare scheduled where the M2M data may be transported. Due to the longdelay tolerance of select M2M applications, M2M data may be accumulatedin the time-domain.

FIG. 6 is a table of OFDMA AMC subcarrier allocations for thenarrow-band (128 bin) case, and those parameters may be applied in boththe DL and in the UL. The guard subcarriers are included to combatout-of-band emissions found in the typical OFDM signal. Although thismay be an issue for the NB-M2M devices in the UL, the full band (allcarriers except DC) may be used for the DL. This may cause an increasein spectral efficiency for the DL. The NB-M2M device may have an RFfront end designed to allow the full spectrum and the baseband processormust process all 128 data points.

The synchronization signals defined for the 128-FFT mode of 802.16e maybe re-used for the NB-M2M devices. For example, the preamble series forthe 128-FFT mode, may be transmitted in the special NB-M2M subband.Rather than transmitting as the first symbol of the DL transmission, theNB-M2M preamble is transmitted as the first NB-M2M symbol in theallocated NB-M2M region (see FIG. 4). The preamble signal is describedas: PreambleCarrierSet_(n)=n+3k, where n is the preamble carrier set andk is a running index, 0-35 for the 128-FFT. This results in a preamblethat uses every 3rd subcarrier, and the subcarrier set depends on thepreamble carrier set in use.

For UL ranging, the NB-M2M device uses the same mechanism defined for802.16e 128-FFT devices. The location of the ranging channel iscommunicated to the NB-M2M MS through the NB-M2M UL MAP.

To balance the complexity at the 802.16e BS and the efficiency of theNB-M2M operation, one of the embodiments for the 802.16e BS MAC maysupport the NB-M2M. First, the MAC design, including MAC PDU, MACcontrol signals, MAC protocols, function modules and MAC procedures, maybe used for the BS to support the NB-M2M devices with the traffic in thenewly proposed NB-M2M regions. Second, the enhanced NB-M2M specific MACdesigns and features may be introduced in an incremental manner at the802.16e BS to improve the NB-M2M operation for the traffic in the NB-M2Mregion, with a proper capability negotiation between the BS and theNB-M2M devices.

The following MAC supports at the BS may be introduced for the NB-M2Moperation, but are not limiting. A first MAC may support small-size MACheaders, extended headers, and control messages. For example, design acompressed MAC header format and MAC control messages just for M2Mtraffic only, (i.e. remove all the unnecessary fields for 802.16e legacytraffic).

A second MAC may use NB-M2M Specific MAC addresses and identifiers. Forexample, using time-division to activate different groups of M2M devicesso that the number of simultaneously active M2M devices can be reduced,thus resulting in a smaller size of address field and/or identifiers.Some address translation/mapping mechanisms can be considered tomaintain the correspondences between the original but longaddresses/identifiers and the compressed addresses/identifiers used atthe MAC layer for the active M2M devices.

A third MAC may use enhanced power saving mechanisms. For example,allowing long sleep/idle intervals, requiring no or minimal paging,introducing new subscriber states and state machines just for M2Mdevices.

A fourth MAC may use enhanced network reentry procedure for M2M devices.For example, allowing different handlings for the M2M device resourceretention timer so that the M2M device context information can beretained at the BS/network with long inactive time periods. In addition,under the consideration of high delay tolerance of certain M2M data,using pre-assigned time and/or frequency to different M2M devices orgroups of M2M devices to spread the network reentry requests in amanaged manner so that a better system loading balance can be achievedand the collision probability in the network re-entry random access canbe significantly reduced.

A fifth MAC may use enhanced random accesses for initial ranging,handover (HO) ranging, periodic ranging, and contention-based ULbandwidth request. For example, periodic ranging may be skipped orminimized due to highly concentrated data bursts from a M2M deviceduring normal M2M operation. HO ranging may be skipped or minimized dueto the consideration of M2M devices being fixed in location for certainM2M applications.

A sixth MAC may use enhanced UL bandwidth request/grant procedures forNB-M2M devices. For example, using a highly coordinated way between thenetwork entry/reentry procedure and UL bandwidth request/grant procedureunder the consideration that most UL traffic from M2M devices is duringa short active period following network entry/re-entry.

In an 802.16e DL, for example, the resources may be allocated in theform of n symbols*m subchannels rectangle by DL MAP IEs. In the 802.16eUL, the resources are allocated by UL MAP IEs in the form of number ofUL resource slots (e.g x symbols*1 subchannel, where x depends on the ULpermutations zones). The DL/UL MAPs may be transmitted to and decoded byall the SSs/MSs, which means all the SSs/MSs know the sizes andlocations of the DL/UL allocations. The 802.16e MSs/SSs may be designedto skip the DL/UL allocations that are not destined to them, and also inDL the 802.16e MSs/SSs may be designed to skip the DL allocations thatthey cannot receive/decode correctly.

While 802.16m systems enjoy the same fixed subcarrier spacing for the 5,10, and 20 MHz bands, there is currently no prescribed structure forbandwidths smaller than 5 MHz. There are at least two options availablethat would allow NB-M2M devices to operate with an 802.16m BS.

One alternative may use some functionality defined for 802.16m's legacymode, which allows 802.16e devices to work with 802.16m base stations byallocating some subframe time to 802.16e frame structures. FIG. 7illustrates an example of 802.16m TDD frame supporting 802.16eoperation.

In FIG. 7, the WirelessMAN-OFDMA and the Advanced Air Interface (AAI)frames 702 and 704, respectively, may be offset by a fixed number of AAIsubframes by frame offset 706, where FRAME_OFFSET=1, 2, . . . , K.Regarding the TDD frame structure supporting WirelessMAN-OFDMA, all ABSswith the same center frequency within the same deployment region shallhave the same FRAME_OFFSET value regardless of ABS type. When theAdvanced Air Interface frames 704 support the WirelessMAN-OFDMA for 5MHz, 10 MHz, 20 MHz channel bandwidths, all AAI subframes in theAdvanced Air Interface DL Zone 708 are type-1 AAI subframes. The numberof symbols in the first WirelessMAN-OFDMA DL Zone 710 is5+6×(FRAME_OFFSET−1). When the Advanced Air Interface frames 704 supportthe WirelessMAN-OFDMA for the 8.75 MHz channel bandwidth with 15 UL OFDMsymbols and for the 7 MHz channel bandwidth with 12 UL OFDM symbols, allAAI subframes in the Advanced Air Interface DL Zone 708 are type-1 AAIsubframes.

The number of symbols in the first WirelessMAN-OFDMA DL Zone 701 may be3+6×(FRAME_OFFSET−1) for 8.75 MHz and 9+6×(FRAME_OFFSET−1) for 7 MHz.The maximum value of parameter K is equal to the number of DL AAIsubframes minus two. The minimum value of FRAME_OFFSET shall be two for8.75 MHz channel bandwidth, and the minimum value of FRAME_OFFSET shallbe one for other bandwidths.

In the DL, a subset of DL AAI subframes may be dedicated to theWirelessMAN-OFDMA operation to enable one or more WirelessMAN-OFDMA DLzones 710. The subset may include the first WirelessMAN-OFDMA DL zone710 to support the transmission of the preamble, FCH and MAP.

The subset of DL AAI subframes dedicated to the WirelessMAN-OFDMAoperation may comprise either one group of contiguous DL AAI subframesor two separate groups of contiguous DL AAI subframes.

When comprising the two separate groups, the second group may includethe last DL AAI subframe. Data bursts for the R1 MSs may not betransmitted in the DL AAI subframes for operation of the Advanced AirInterface. Those DL AAI subframes shall be indicated as a DL time zoneby transmitting an STC_DL_ZONE_IE( ) with the Dedicated Pilots field setto 1 in the DL-MAP messages.

DL/UL MAPs and bursts for AMS may be scheduled in either zone (AdvancedAir Interface DL Zone 708 or WirelessMAN-OFDMA DL Zone 710) according tothe mode (Advanced Air Interface or WirelessMANOFDMA) with which the AMSis connected to the ABS, but shall not be scheduled in both zones in thesame frame.

In the UL, the following configurations may be applicable. In FDM mode,a group of subcarriers (subchannels), spanning the entire ULtransmission, is dedicated to the WirelessMAN-OFDMA operation. Theremaining subcarriers, denoted the Advanced Air Interface UL subchannelsgroup and forming the Advanced Air Interface UL AAI subframes, arededicated to the Advanced Air Interface operation.

In case that PUSC subchannel rotation is activated for R1 MSs, ABS shalltransmit TLV 157 of the UCD i.e., “UL allocated subchannels bitmap” forMSs to recognize the available subchannels. Available subchannels for R1MSs shall be logically contiguous in terms of subchannel index and shallnot be allocated for AMSs.

Data bursts from the R1 MSs may not be transmitted in the UL subchannelsgroup for operation of the Advanced Air Interface. Control channels andbursts for AMS may be scheduled in either group of UL subchannels (groupof UL subchannels for Advanced Air Interface or WirelessMAN-OFDMA)according to the mode (Advanced Air Interface or WirelessMAN-OFDMA) withwhich the AMS is connected to the ABS, but may not be scheduled in bothgroups in the same frame.

FIG. 8 is an example of an 802.16m with wireless MAN-OFDMA legacy frameoperating for NB-M2M. While the legacy mode in 802.16m is defined foruse of the full bandwidth, a narrow band portion as shown in FIG. 8 maybe used to insert a legacy frame for NB-M2M devices while the remainingbandwidth is used for 802.16m devices. This is similar to the techniqueused for 802.16e systems, except the NB-M2M allocation is accommodatedby allocating a time/frequency block with a narrow bandwidth, treatingthat block as a narrowband 802.16e UL/DL area, and simultaneously usingthe remaining bandwidth for 802.16m communications. Any controlstructures or other system definitions prescribed for the 802.16eversion may apply to the WirelessMAN-OFDM mode of 802.16m.

Another alternative may define a narrowband 802.16m configuration,similar to what was done in 802.16e for the 128-FFT, and allocate aportion of the frame for an NB-M2M structure, again, similar to what wasdone for 802.16e. While this option requires more structural additionsto 802.16m, it would allow a “pure” 802.16m system without the need forlegacy support.

Similar supports to those described above may be used with an 802.16mABS (Advanced BaseStation) to accommodate the NB-M2M operation in the802.16m systems.

Similarly, the 802.16m Advanced Mobile Station (AMS) may be designed toskip the DL/UL allocations that are not destined to it.

The NB-M2M devices transmit and receive in a narrowband channel, e.g.,1.25 MHz, and are designed to be cost-effective and power-efficient forthe M2M applications with low data traffic and small data bursts. TheNB-M2M devices may be supported in some existing wideband wirelessaccess systems, such as, 802.16e, 802.16m, and 3GPP LTE/LET-A, inaddition to NB-M2M access systems.

The following discusses the NB-M2M devices supported in the existingwideband wireless access systems, including but not limited to 802.16e,802.16m, and 3GPP LTE/LTE-A. The NB-M2M devices as a new subscriber typein the 802.16p systems are proposed. Since both 802.16e OFDMA systemsand 802.16m systems are considered as baseline systems for the 802.16pdevelopment, the proposed NB-M2M devices need to be supported in the802.16e-based 802.16p systems and the 802.16m-based 802.16p systems.

In 802.16p systems, the NB-M2M devices may transmit and receive in theNB-M2M regions as allocated by the BS, as shown in the example in FIG.4. The NB-M2M devices may be designed to process the radio frames withdiscontinuous DL areas (frequency domain*time domain) that they may ormay not receive/decode correctly and discontinuous UL areas that theymay or may not transmit.

The NB-M2M devices may support the subscriber side narrowband PHY designand processing, to communicate with the BS in the NB-M2M region asdescribed above.

The NB-M2M devices may support the 802.16 MAC design and procedures forthe basic support of NB-M2M operation in 802.16p systems. In addition,the NB-M2M devices may support the capability negotiation signaling andprocedures with the BS to initialize any NB-M2M specific MACenhancements as described above. The NB-M2M devices can also support theMAC enhancements as described above.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

Embodiments

1. A method for use in a wireless communication system, the methodcomprising allocating a narrowband structure inside of a widebandstructure to access a frame structure, wherein the narrowband structureis allocated using a base station such that the narrowband structureincludes spectrum for Machine-to-Machine (M2M) communications.

2. The method as in embodiment 1, wherein s preamble for a band isembedded within s downlink frame to allow the M2M device to synchronizeto s base station.

3. The method as in any of the preceding embodiments, wherein thenarrowband structure is allocated such that the base station maycommunicate with M2M devices in channels with narrowband bandwidth.

4. The method as in any of the preceding embodiments, wherein thenarrowband structure is allocated to satisfy quality of service (QoS)requirements for M2M communications and to minimize impact on otherdevices in the wireless communication system.

5. The method as in any of the preceding embodiments, wherein the basestation supports a narrowband (NB)-M2M region specific physical layer(PHY).

6. The method as in any of the preceding embodiments, wherein the basestation supports an NB-M2M device specific medium access control layer(MAC).

7. The method as in any of the preceding embodiments further comprisingusing a localized subcarrier allocation in LTE.

8. The method as in any of the preceding embodiments, wherein asubcarrier mapping is used to allocate a portion of the bandwidth tonarrow band M2M (NB-M2M) devices

9. The method as in any of the preceding embodiments, wherein a regularframe structure is used.

10. The method as in any of the preceding embodiments, wherein thenarrow band structure starts with an M2M preamble, followed by data.

11. The method as in any of the preceding embodiments, wherein anydownlink transmissions specific to M2M devices in the narrowbandstructure are identified by an M2M map.

12. The method as in any of the preceding embodiments, wherein an M2Muplink space within a special narrowband structure is allocated by thebase station and used by M2M devices.

13. The method as in any of the preceding embodiments, wherein asampling frequency is calculated as F_(s)=floor (n·BW/8000)·8000, wheren is the sampling factor.

14. The method as in any of the preceding embodiments wherein asubcarrier spacing is calculated as Δf=F_(s)/N_(FFT), where N_(FFT) isthe smallest power of two greater than the number of subcarriers in use.

15. The method as in any of the preceding embodiments, wherein thesubcarrier spacing does not match the value for the band and changes tothe band parameters are made.

16. The method as in any of the preceding embodiments, wherein thepreamble for a band is embedded within the downlink frame to allow theM2M device to synchronize to the base station.

17. The method as in any of the preceding embodiments, wherein NB-M2Mtraffic is supported in a Time Division Multiplexing (TDM) manner.

18. The method as in any of the preceding embodiments, wherein NB-M2Mtraffic is supported in a Frequency Division Multiplexing (FDM) manner.

19. The method as in any of the preceding embodiments, wherein a FrameControl Header (FCH) is included in the frame to allow NB mobilestations to use.

20. A method for use in a wireless communications system, the methodcomprising: transmitting M2M signals, the signals are transmitted in anallocated narrow portion of bandwidth in a wideband structure, whereinthe allocated portion of the bandwidth is allocated to narrow band M2M(NB-M2M) devices using a low complexity narrowband technology to accessa frame structure within an existing wideband deployment.

What is claimed is:
 1. A method for use in a wireless communicationsystem, the method comprising allocating a narrowband structure insideof a wideband structure to access a frame structure, wherein thenarrowband structure is allocated using a base station such that thenarrowband structure includes spectrum for Machine-to-Machine (M2M)communications.
 2. The method as in claim 1, wherein s preamble for aband is embedded within s downlink frame to allow the M2M device tosynchronize to s base station.
 3. The method as in claim 1, wherein thenarrowband structure is allocated such that the base station maycommunicate with M2M devices in channels with narrowband bandwidth. 4.The method as in claim 1, wherein the narrowband structure is allocatedto satisfy quality of service (QoS) requirements for M2M communicationsand to minimize impact on other devices in the wireless communicationsystem.
 5. The method as in claim 1, wherein the base station supports anarrowband (NB)-M2M region specific physical layer (PHY).
 6. The methodas in claim 1, wherein the base station supports an NB-M2M devicespecific medium access control layer (MAC).
 7. The method as in claim 1further comprising using a localized subcarrier allocation in LTE. 8.The method as in claim 1, wherein a subcarrier mapping is used toallocate a portion of the bandwidth to narrow band M2M (NB-M2M) devices9. The method as in claim 8, wherein a regular frame structure is used.10. The method as in claim 8, wherein the narrow band structure startswith an M2M preamble, followed by data.
 11. The method as in claim 8,wherein any downlink transmissions specific to M2M devices in thenarrowband structure are identified by an M2M map.
 12. The method as inclaim 8, wherein an M2M uplink space within a special narrowbandstructure is allocated by the base station, indicated by an M2M map, andused by M2M devices.
 13. The method as in claim 1, wherein a samplingfrequency is calculated as F_(s)=floor (n·BW/8000)·8000, where n is thesampling factor.
 14. The method as in claim 1, wherein a subcarrierspacing is calculated as Δf=F_(s)/N_(FFT), where N_(FFT) is the smallestpower of two greater than the number of subcarriers in use.
 15. Themethod as in claim 1, wherein the subcarrier spacing does not match thevalue for the band and changes to the band parameters are made.
 16. Themethod as in claim 1, wherein the preamble for a band is embedded withinthe downlink frame to allow the M2M device to synchronize to the basestation.
 17. The method as in claim 1, wherein NB-M2M traffic issupported in a Time Division Multiplexing (TDM) manner.
 18. The methodas in claim 1, wherein NB-M2M traffic is supported in a FrequencyDivision Multiplexing (FDM) manner.
 19. The method as in claim 1,wherein a Frame Control Header (FCH) is included in the frame to allowNB mobile stations to use.
 20. A method for use in a wirelesscommunications system, the method comprising: transmitting M2M signals,the signals are transmitted in an allocated narrow portion of bandwidthin a wideband structure, wherein the allocated portion of the bandwidthis allocated to narrow band M2M (NB-M2M) devices using a low complexitynarrowband technology to access a frame structure within an existingwideband deployment.